Temperature-controlled time-varying bionic adhesion structure and regulation method for rapid switching of adhesion / desorption

Abstract

A temperature-controlled time-varying bionic adhesion structure for rapid switching of adhesion / desorption and a control method, the structure comprises two layers, a top layer is a dry adhesion structure layer, a bottom layer is an external field driving layer, and the bottom layer is surrounded by a supporting structure; the dry adhesion structure layer is a mushroom-shaped array structure, and the external field driving layer is an electric heating film that provides temperature changes; the dry adhesion structure layer adopts liquid crystal elastic polymer LCE; the control method is that in the absence of an electric field, the dry adhesion structure layer maintains an initial morphology, and the dry adhesion structure layer has high-strength adhesion characteristics; when an electric field is applied, the electric heating film generates an electric heating effect, causing the dry adhesion structure layer to undergo thermal shrinkage deformation, and the adhesion interface between the dry adhesion structure layer and the adherend is separated, thereby achieving desorption; when the electric field is removed, the electric heating effect of the electric heating film disappears, the dry adhesion structure layer restores its initial morphology under the action of elasticity, and the dry adhesion structure layer recovers its high-strength adhesion characteristics; the present invention realizes the organic unity of high-strength adhesion and controllable desorption.

Description

Technical Field

[0001] The invention belongs to the technical field of micro-nano engineering bionic design, and specifically relates to a temperature-controlled time-varying bionic adhesion structure for rapid switching of adhesion / desorption and a control method. Background Art

[0002] Geckos can crawl on vertical surfaces and ceilings easily and freely by relying on the van der Waals force between the fine micro-nanostructure at the end of their toes and the surface of objects. They have the advantages of strong adhesion, good stability, strong adaptability to materials and morphology, good self-cleaning, and will not damage or pollute the surface of objects. This is called dry adhesion. At present, dry adhesion functional surfaces have replaced traditional adhesion methods and have become an important direction and trend in the development of bionic wall-climbing robots, non-destructive precision transportation in space environments / ultra-clean environments, and biomedical diagnosis.

[0003] In the application process of dry adhesion structure surface, how to achieve high-strength adhesion and controllable desorption is an important aspect in the field of dry adhesion research. Using mushroom-shaped array structure to achieve high-strength adhesion is an effective adhesion method. However, due to the symmetry of the morphology, the mushroom-shaped array structure shows equal adhesion strength in all directions and cannot achieve effective controllable desorption. Using anisotropic microstructure functional surfaces such as inclined microstructure array (DOI: 10.1063 / 1.3006334), triangular micro-pillar array (DOI: 10.1002 / smll.201100455) and defective micron-level cap end (DOI: 10.1088 / 1748-3182 / 8 / 4 / 044002), controllable desorption of adhesion surface can be achieved, but the premise is at the expense of adhesion strength. Therefore, how to achieve the organic unity of high-strength adhesion and controllable desorption of dry adhesion functional surface is the difficulty and challenge faced by the current dry adhesion structure design and process manufacturing direction. Summary of the invention

[0004] In order to solve the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a temperature-controlled time-varying bionic adhesion structure and a control method for rapid switching of adhesion / desorption, so as to achieve the organic unity of high-strength adhesion and controllable desorption.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A temperature-controlled time-varying bionic adhesion structure for rapid switching of adhesion / desorption comprises a two-layer structure, a top layer being a dry adhesion structure layer, a bottom layer being an external field driving layer, and the surroundings of the bottom layer being support structures.

[0007] The dry adhesion structure layer is a mushroom-shaped array structure, and the external field driving layer is an electric heating film that provides temperature changes.

[0008] The dry adhesion structure layer is made of liquid crystal elastic polymer LCE; the electric heating film is in the form of flexible electric heating film such as carbon nanotubes, iron chromium aluminum, etc.; and the supporting structure is made of dielectric material.

[0009] The preparation process of the dry adhesion structure layer is as follows: first, an inverse structure of a mushroom-shaped array structure is prepared, and a voltage is applied between the inverse structure and the substrate so that the liquid crystal elastic polymer LCE in the inverse structure cavity quickly fills the entire cavity to form a mushroom-shaped array structure with an adhesion function, and at the same time generates orientation, that is, it has the characteristic of thermal shrinkage.

[0010] The method for regulating a temperature-controlled time-varying bionic adhesion structure for rapid switching of adhesion / desorption comprises the following steps:

[0011] In the first step, in the absence of an electric field, the dry adhesion structure layer maintains its initial morphology and has high-strength adhesion properties;

[0012] The second step is to apply an electric field, and the electric heating film generates an electric heating effect under the action of the electric field, causing the dry adhesive structure layer to undergo thermal shrinkage deformation, and the adhesion interface between the dry adhesive structure layer and the adherend to separate, thereby achieving desorption;

[0013] In the third step, the electric field is removed, the electric heating effect of the electric heating film disappears, the dry adhesion structure layer restores its original morphology under the action of elasticity, and the dry adhesion structure layer recovers its high-strength adhesion characteristics.

[0014] Beneficial effects of the present invention: The dry adhesion structure layer based on liquid crystal elastic polymer LCE of the present invention can utilize the thermal actuation characteristics of liquid crystal elastic polymer to achieve controllable desorption and adhesion of the dry adhesion functional structure under temperature control while maintaining high adhesion strength of the adhesion structure. The temperature-controlled time-varying bionic adhesion structure for rapid switching of adhesion / desorption of the present invention can be widely used in dry adhesion fields such as belt conveyors, manipulators, and micro suction cups. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the temperature-controlled time-varying bionic adhesion structure of the present invention.

[0016] Figure 2 Schematic diagram of the preparation of the dry adhesion structure of the present invention.

[0017] Figure 3 It is a schematic diagram of the orientation of the liquid crystal elastic polymer of the present invention.

[0018] Figure 4 It is a schematic diagram of the temperature-controlled and time-varying bionic adhesion structure of the present invention when there is no electric field.

[0019] Figure 5 It is a schematic diagram of the deformation of the temperature-controlled time-varying bionic adhesion structure when an electric field is applied in the present invention. DETAILED DESCRIPTION

[0020] The present invention is described in detail below with reference to the accompanying drawings.

[0021] Reference Figure 1 A temperature-controlled time-varying bionic adhesion structure for rapid switching of adhesion / desorption comprises a two-layer structure, the upper layer is a dry adhesion structure layer 5, and the dry adhesion structure layer 5 is a mushroom-shaped array structure; the bottom layer is an external field driving layer, and the external field driving layer is an electric heating film 6 that provides temperature changes; the bottom layer is surrounded by a supporting structure 4.

[0022] The dry adhesion structure layer 5 is made of liquid crystal elastic polymer LCE; the electric heating film is in the form of a flexible electric heating film such as carbon nanotubes, iron chromium aluminum, etc.; and the supporting structure 4 is made of dielectric material.

[0023] The preparation process of the dry adhesion structure layer 5 is as follows: first, an inverted structure 1 of a mushroom-shaped array structure is prepared, and a proper voltage is applied between the inverted structure 1 and the substrate 3, so that the liquid crystal elastic polymer LCE 2 in the cavity of the inverted structure 1 quickly fills the entire cavity, such as Figure 2 As shown, during the filling process, the liquid crystal elastic polymer LCE 2 is oriented at the same time, that is, it has the characteristic of thermal shrinkage, such as Figure 3 shown.

[0024] The method for regulating a temperature-controlled time-varying bionic adhesion structure for rapid switching of adhesion / desorption comprises the following steps:

[0025] In the first step, in the absence of an electric field, the dry adhesive structure layer 5 maintains its initial shape and does not shrink or deform. The dry adhesive structure layer 5 has high-strength adhesive properties, such as Figure 4 As shown;

[0026] In the second step, an electric field is applied. The electric heating film 6 generates an electric heating effect under the action of the electric field. The heat generated causes the dry adhesive structure layer 5 to undergo thermal shrinkage deformation. The adhesive interface between the dry adhesive structure layer 5 and the adherend 7 separates, thereby achieving desorption. Figure 5 As shown;

[0027] In the third step, the electric field is removed, the electric heating effect of the electric heating film 6 disappears, the temperature decreases, the dry adhesion structure layer 5 restores the original morphology under the action of elasticity, and the dry adhesion structure layer 5 recovers the high-strength adhesion property.

Claims

1. A temperature-controlled time-varying bionic adhesion structure for rapid switching of adhesion / desorption, characterized in that: It includes two layers, the top layer is a dry adhesion structure layer, the bottom layer is an external field driving layer, and the surrounding of the bottom layer is a supporting structure; The dry adhesion structure layer is a mushroom-shaped array structure, and the external field driving layer is an electric heating film that provides temperature changes; The dry adhesion structure layer is made of liquid crystal elastic polymer LCE; the electric heating film is in the form of a flexible electric heating film of carbon nanotubes and iron chromium aluminum; the supporting structure is made of dielectric material; The preparation process of the dry adhesion structure layer in the temperature-controlled time-varying bionic adhesion structure is to first prepare an inverse structure of a mushroom-shaped array structure, apply a voltage between the inverse structure and the substrate, so that the liquid crystal elastic polymer LCE in the inverse structure cavity quickly fills the entire cavity, forming a mushroom-shaped array structure with adhesion function, and at the same time generates orientation, that is, it has the characteristic of thermal shrinkage.

2. The method for controlling a temperature-controlled time-varying bionic adhesion structure for rapid switching of adhesion / desorption according to claim 1, characterized in that: The following steps are involved: In the first step, in the absence of an electric field, the dry adhesion structure layer maintains its initial morphology and has high-strength adhesion properties; The second step is to apply an electric field, and the electric heating film generates an electric heating effect under the action of the electric field, causing the dry adhesive structure layer to undergo thermal shrinkage deformation, and the adhesion interface between the dry adhesive structure layer and the adherend to separate, thereby achieving desorption; In the third step, the electric field is removed, the electric heating effect of the electric heating film disappears, the dry adhesion structure layer restores its original morphology under the action of elasticity, and the dry adhesion structure layer recovers its high-strength adhesion characteristics.

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